Traffic Javascript logic improvements and cleanup.
Traffic Javascript logic improvements and cleanup.

Fixes case where aircraft is first placed into “invalid position” table
and is never removed (even when position becomes valid).

cyoung/stratux,ssokol/stratux,timami/stratux,timami/PlaneSense,timami/PlaneSense,jpoirier/stratux,westphae/stratux,cyoung/stratux,timami/PlaneSense,westphae/stratux,cyoung/stratux,timami/stratux,timami/PlaneSense,lukepalmer/stratux,timami/PlaneSense,cyoung/stratux,cyoung/stratux,jpoirier/stratux,ssokol/stratux,ssokol/stratux,lukepalmer/stratux,westphae/stratux,westphae/stratux,lukepalmer/stratux,ssokol/stratux,timami/stratux,timami/stratux,lukepalmer/stratux,jpoirier/stratux,jpoirier/stratux,timami/stratux,timami/PlaneSense,timami/stratux,lukepalmer/stratux,jpoirier/stratux,ssokol/stratux,ssokol/stratux,cyoung/stratux,westphae/stratux,jpoirier/stratux,westphae/stratux,lukepalmer/stratux